This was one of my favorite spots in Toronto. I love the 3D TORONTO sign. Good luck trying to take a picture without other people in it though. It's situated in front of New City Hall and to the left of Old City Hall (National Historic Site of Canada), which are both impressive buildings. The square features a reflecting pool that turns into a skating rink in the colder months. Without the skating rink or any events going on, there isn't much to actually do there. It was a nice place to take a break, enjoy your lunch, and people watch.
FYI- In case you're wondering who Nathan Phillips is, he was a former mayor of Toronto